Harmonic tone putter

ABSTRACT

This invention embodies golf clubs and heads providing visual, auditory, and/or tactile aids useful to a golfer in determining whether a golf ball has been accurately struck. The head of the golf club is designed to produce a fundamental musical tone upon impact with a golf ball at the sweet spot of the club face. When a golf ball is struck at areas outside of the sweet spot, the head produces audible harmonic overtones that resonate above the fundamental pitch. Furthermore, the shaft of the golf club is preferably made from a resonant material that is attached to the head at a vibratory node of the head such that when a golf ball has been accurately struck using the sweet spot of the club face, no harmonic vibrations are transferred along the shaft to the grip.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. provisional applicationserial No. 60/434,309, filed Dec. 17, 2002.

BACKGROUND

[0002] Golf putters, and other short-range golf clubs such as chippers,come in a wide variety of designs and styles, each designed with theintention of either improving control or acting as a teaching aid, forthe novice and experienced golfers alike. Design attributes include clubhead shape, the method of attaching the shaft to the putter head, theparameters chosen for the shaft, the overall club head weight, thedistribution of the weight from toe to heel or the face relative to theback, and the use of different sound- and/or vibration-producingmechanisms to indicate proper technique.

[0003] Numerous golf club heads incorporate sound chambers or othertypes of sound-producing features into their design such that adiscernible sound and/or other vibration is produced when a ball isstruck with the club face.

[0004] For example, U.S. Pat. Nos. 5,160,144; 5,551,694; and 4,123,056are all directed to sound-producing putters that are based, in part, onthe principles of tuning forks in which the vibration of tines producesa tone. U.S. Pat. Nos. 5,346,219; 5,803,825; 4,113,249; 5,322,285; andU.S. patent application Publication No. 2002/0055394 all describe golfclubs for producing sound that utilize various sound chambers formedwithin the main body of a golf club head. Other golf clubs withsound-producing heads are also known, including those described in U.S.Pat. Nos. 4,383,690; 5,718,641; 6,406,378; and 5,830,084.

[0005] It is desirable in the design of a golf club to provide auditory,visual, and tactile aids to help a golfer correct an inaccurate golfswing and/or to indicate to a golfer when a golf ball has been hitproperly using the “sweet spot” (an area on the face that, when strikinga golf ball, provides optimum control to the golfer).

[0006] A club is also desirable that compensates for an inaccurate swingby mitigating the swing's negative impact on the speed and direction ofthe hit ball. It is further desirable that the structure of a golf cluballows greater control over the speed and direction of a golf ball whenit is hit properly, and that a golfer is easily able to choose a golfclub, or a head for a given shaft based on course conditions (e.g., turfhaving high or low moisture content).

[0007] All references cited herein are incorporated in their entirety tothe extent not inconsistent herewith.

SUMMARY OF THE INVENTION

[0008] The present invention provides golf club heads and golf clubs,incorporating auditory, tactile, and visual aids useful to a golfer toindicate when a golf ball has been struck properly and/or to correct foran inaccurate golf swing. Specifically, the golf club of this inventioncomprises a head that produces a dominant fundamental tone when used tostrike a golf ball. A shaft made of resonant material is joined to thehead at one of two vibratory nodes within the head. The resonantmaterial is matched to the club head such that when a golf ball isstruck correctly, each vibrate to their fundamental frequency and arenot felt by the golfer within the grip. When a golf ball impacts theface of the club outside of the sweet spot, vibrations are felt by thegolfer at the grip due in part to the overtones generated in the shaftand club head.

[0009] In one embodiment of this invention, the golf club head is shapedsuch that when a golf ball is hit incorrectly, the overtones (noteshaving frequencies that are whole-number multiples of the fundamentaltone) produced by the vibrating head become more audible or detectableand indicate to a golfer that he has not properly hit the ball. Thevibrations associated with these overtones are maximized at thevibratory nodes. Optionally the vibrations are transferred to the shaft.

[0010] It is an object of the present invention to provide a golf clubthat produces a ringing tone when used to strike a golf ball. It isfurther an object of this invention to provide a ‘window’ in the head ofthe golf club such that the line of the club's swing may be seen by thegolfer. It is further an object of this invention to provide a golf clubputter that minimizes jumping, skipping, or sliding of a golf ball uponcontact with the putter face, and that minimizes the negative effects ofan inaccurate swing on a golf ball's distance or direction.

[0011] This invention provides a golf club comprising: a head made of afirst material capable of producing a tone, preferably a selectedmusical note, when struck by a golf ball, and having at least onevibratory node; and a shaft made of a resonant material attached to saidhead at said vibratory node wherein the first material is selected fromthe group consisting of metals, including metal alloys, ceramics, wood,polymers, and glass. Preferably, the first material is aluminum orbronze and the head has a weight between about 250 g and about 500 g.

[0012] In one embodiment of this invention, the golf club head is madeof a single piece of metal having two free ends which face but do nottouch each other at the back of said head to form a space between saidtwo ends wherein the pitch of the tone capable of being produced can betuned by changing the size of the space. In an embodiment of thisinvention, the free ends are on the back of the head, opposite the face,and they face each other. Optionally, the tone may be dampened byplacing a baffle in the space, such that the baffle touches both sidesforming the space. The baffle can be made of any material that dampensthe sound, including rubber and foam. In an embodiment of thisinvention, a head is designed to have the tone dampened by including adamping hole through the free ends to allow for a baffle to be inserted,optionally requiring a tool. In embodiments of the invention, thedamping hole extends from the top to the bottom or from the back to thehole.

[0013] In embodiments of this invention, the head has a thickness fromtop to bottom that is thinner than, about the same as, or thicker thanthat the diameter of a standard golf ball, and at least about one inch.The head further comprises a cylindrical hole (also called a “window”)formed therethrough from top to bottom, the size and/or shape of whichmay be changed to alter the pitch produced by the club. The distancebetween the face of the club head and the edge of the cylindrical holeis between about three sixteenths of an inch and one inch, about onefourth and about three quarters of an inch, or about three-eighths andabout five-eighths of an inch. The top and bottom of the head may besubstantially planar, but may also be curved or rounded.

[0014] In another embodiment of this invention, the head of the golfclub of this invention is a solid bar that optionally has a portion ofits material cut away at the rear of the club centered behind the sweetspot.

[0015] In other embodiments of this invention, the plane of the face ofsaid head is angled toward the back of the head at about 1 to about 65degrees from the bottom to the top of said face. Alternatively, thebottom of said club head is angled upward from about 1 to about 65degrees from the face to the back such that when the bottom sits flushwith the ground the face of the club is angled back.

[0016] The face optionally further comprises mill lines, such as areformed by a milling process, that are linear or nonlinear. Golf clubheads embodying by this invention may also optionally comprise a markingor markings on the top of said head indicating that the “sweet spot” islocated at a corresponding lateral location relative to the toe and heelon the face of the head, e.g., a straight line having a constantdistance from the toe and heel sides of the head to the face may markthe center of the “sweet spot.”

[0017] In one embodiment of this invention, the shaft is made ofhardwood selected from a group of woods known for their acousticalproperties and widely used in the building of fine musical instruments.These “tone-woods” include pernambuco, rosewood, vermillion, granadillo,ebony and osage orange. Alternatively, the shaft is made from steel,graphite, carbon fiber, plastic, or Keylon™ (a plastic formulated, forexample, for use in the manufacture of synthetic xylophone bars).Materials useful in the practice of this invention include materials notyet utilized in the construction of golf clubs and golf club components,including materials useful for construction of musical instruments.

[0018] In one embodiment of this invention, the shaft of the golf clubof this invention is attached to the head at the vibratory node of thehead via a hole in the head adapted to receive the shaft. In oneembodiment, a tapered hole is utilized for fitting a tapered end ofshaft. A tapered connector (a “hosel”) may be used having one endadapted to receive an end of said shaft. The tapered connector mayfurther comprise a hexagonally shaped nut above the section insertedinto the head to assist in securing or removing the shaft from the head.Alternatively, the head can be formed to have an impression on thebottom, such as a hemispheric indentation, in line with the nodal axis,for attaching a shaft using a drive pin and a hammer. In one embodimentof this invention, the shaft and head can only be attached, adjusted, orseparated using a tool.

[0019] In one embodiment of a golf club of this invention, the shaftcomprises a rounded top designed to fit against the navel of a golfer.This rounded top is preferably substantially ball-shaped and isoptionally formed on a segment that is removable from the shaft, whereinthe removable segment comprises a tapered bottom. The shaft may furthercomprise a cap having a tapered hole to receive the tapered bottom ofthe removable segment. Preferably the rounded top is not removable fromthe shaft. Preferably the rounded top is constructed from a materialhaving similar vibrational qualities as the shaft. Preferably the shaftand rounded top are made from the same material. Preferably the shaftand rounded top are constructed from the same piece of material.

[0020] Preferably, the golf club of this invention is a putter, chipper,or other short-range club.

[0021] This invention further provides for a set of golf clubsconstructed and adapted to produce separate or detectably distinctselected musical notes when each strikes or hits a golf ball. In anembodiment of this invention, each of the club heads is assigned amarking, e.g., color, texture, or pitch symbol, indicative of the noteeach produces when it strikes a golf ball.

[0022] This invention further provides a method for hitting a golf ballcomprising positioning a golf club of this invention adjacent to thegolf ball; and striking or hitting the golf ball with the head of thegolf club to produce a musical note or tone. As used herein, “hit”refers to contact resulting in production of a musical tone or note.Optionally a hit is preceded by a swing.

[0023] This invention also provides a method for hitting a golf ball ona course having particular conditions affecting golf ball speed. With agolf club of this invention, said method comprising determining thecondition of the golf course and choosing a head from said set of headsin accordance with said conditions.

[0024] A method is also provided for determining when a golf club hashit a golf ball at the golf club head's sweet spot, said methodcomprising: hitting the golf ball with a club of this invention; anddetermining that the golf ball has been hit at the golf club's sweetspot by detecting when the head produces a fundamental musical toneindicative of having hit the ball with the sweet spot. This methodfurther comprises determining that the golf ball has been hit by thegolf club's sweet spot by feeling or otherwise detecting minimum or novibration at the grip of the shaft. Detecting a fundamental tone canoccur by any means known in the art including by a human ear or acomputer. Detecting minimum or no vibration can occur by any means knownin the art including by human hands or navel.

[0025] As used herein, the term ‘substantially planar’ refers to asurface that, when placed against a planar surface, at least two pointsof the surface are in contact with the planar surface. Substantiallyplanar surfaces include for example, surfaces which are planar, planarsurfaces with rounded edges and flat surfaces in which a part of thesurface material is removed, and/or in which a planar portion of asurface is in contact with one or more curved portions of a surface.

[0026] As used herein, the term ‘vibratory node’ indicates a point,line, or area on the golf club head surface, which extends through across section of the head, at which, when the rest of the head vibratesto produce a fundamental tone, there are no or minimum vibrations inthis area arising from the fundamental tone.

[0027] The term ‘resonant material’ as used herein indicates a materialthat can be used as a shaft for the golf club of this invention that isjoined to the head at the head's vibratory node such that when the faceof the head is struck at its sweet spot, although vibrations areproduced resulting in a fundamental tone or note by the head, minimalenergy and/or vibrations are transferred to the shaft with minimum or novibration felt by the golfer at the grip. Preferably a resonant materialis selected that does not interfere with transfer of vibrational energy.

[0028] The term ‘solid’ refers to a material that is not hollow, or doesnot have any completely contained cavities within. Solid materialsinclude materials with partially contained cavities.

[0029] The terms “toe and heel” as used herein refer to the sides of thegolf club head that are farthest from and closest to, respectively, thegolfer's feet when the golf club is in use.

[0030] As used herein, the term ‘fundamental tone’ refers to the primarytone produced by the golf club of this invention when struck at itssweet spot. An ‘overtone’ is an integral multiple of the frequency ofthe fundamental tone, e.g. the ‘first overtone’ is two times thefrequency of the fundamental tone. The term ‘harmonic’ is also used toreference integral multiples of the fundamental tone (the firstharmonic).

[0031] The term ‘to tune’ is used herein to refer to changing thefundamental tone produced by the golf club head.

[0032] “Cylindrical” is used as in the art and is intended to includegeneralized cylinders, cylinders that have parallel sides that areperpendicular to the bottom, cylinders having one radius wherein thecross-section is a circle, cylinders having a textured face, andcylinders wherein on average the axes of one or more sides are parallel,but in a small section the sides are not parallel, e.g., the sides arerippled. A head having a hole having one or more small sections whichare not parallel, can be designed to produce a selected number offundamental tones.

[0033] A standard golf ball is one that is recognized as legal for playby the PGA, the LPGA, and/or other international bodies governing golf.

BRIEF DESCRIPTION OF THE DRAWINGS

[0034]FIGS. 1A and 1B are angled top view illustrations of two golf clubheads of this invention, each comprising a solid bar.

[0035] FIGS. 2A-2C are illustrations of a golf club head of thisinvention. FIG. 2A is a top view. FIG. 2B is a side view of the back.FIG. 2C is a side view.

[0036]FIG. 3 is an angled top view illustration of a golf club of thisinvention.

[0037] FIGS. 4A-4C are illustrations of the golf club head of the clubshown in FIG. 3. FIG. 4A is a top view. FIG. 4B is a side view. FIG. 4Cis a side view.

[0038]FIGS. 5A and 5B are illustrations of a golf club head of thisinvention. FIG. 5A is a top view. FIG. 5B is a side view.

[0039] FIGS. 6A-6D are top view illustrations of golf club heads of thisinvention.

[0040]FIGS. 7A and 7B are illustrations of golf club heads of thisinvention. FIG. 7A is a top view. FIG. 7B is a side view.

[0041]FIGS. 8A and 8B are illustrations of golf club heads of thisinvention. FIG. 8A is a top view. FIG. 8B is a side view.

[0042]FIGS. 9A and 9B are illustrations of golf club heads of thisinvention. FIG. 9A is a top view. FIG. 9B is a side view.

[0043]FIG. 10 illustrates the top of a shaft of a golf club of thisinvention, having a rounded navel knob.

[0044] FIGS. 11A-11C are illustrations of a golf club head of thisinvention not having an open sight line. FIG. 11A is a top view. FIGS.11B and 11C are cross sections as marked.

DETAILED DESCRIPTION OF THE INVENTION

[0045] The golf club of this invention comprises a head made of amaterial capable of producing a fundamental tone when struck on itsface. The face comprises a zone known as the ‘sweet spot’ that whenstruck, maximizes the fundamental tone and minimizes the overtoneseries. To minimize damping of the vibrations associated with thefundamental tone, the shaft of the golf club attaches to the head at thevibratory node. By attaching the shaft to a vibratory node, the transferof vibrations arising from the fundamental tone from the head to theshaft is negligible, and the predominant vibrations in the shaft arisefrom the bending of the shaft when the golf ball is struck.

[0046] As the face is struck outside of but closer to the ‘sweet spot’,the harmonics become more predominant, and are maximized at thevibratory nodes. The overtones are minimized at the nodes.

[0047] The club head is frequency-matched to the shaft as to allow thehead, when struck, to maintain a sustained fundamental tone withoutbeing dampened or diminished by a shaft producing frequencies dissonantto the club head's fundamental tone and/or harmonic series. One ofordinary skill in the art will be able to select a suitable shaft forthe club heads of this invention, without undue experimentation.

[0048] The tones produced by the clubs of this invention can encompassany audible or otherwise detectable range. Preferably, the tones rangefrom 300 Hz to 1200 Hz and depend on the shape and size of the head, aswell as the material from which the head is made. The tone that isproduced is the result of resonant vibration of the head. When a golfball strikes the sweet spot on the face of a golf club of thisinvention, energy is transferred both to the club head, resulting invibrations producing a sound, and to the golf ball, resulting in theball's traveling away from the club face. Efficiency of the transfer ofenergy of impact is reflected in the production of a clear, ringing tonewhen using the golf club of this invention. The efficient transfer ofthe energy of impact is also reflected in the smooth transfer of energyto the ball, resulting in less jumping, skidding, or skipping of theball as it leaves the club face.

[0049] The pitch of the fundamental tone produced by a head of the golfclub of this invention in part corresponds to the amount of energytransferred between the club head and the ball, and thus plays a role inhow far a ball hit with the club will travel under identical conditions(e.g. weight and club head proportions, force with which the ball ishit, surface conditions and the like). Golf clubs having heads thatproduce different fundamental tones will transmit different amounts ofenergy to a golf ball than those producing other fundamental tones,resulting in different distances traveled by the ball. This effect canbe useful to a golfer in choosing a club head that is best suited tocourse conditions, e.g. wet and slow, or dry and fast.

[0050] In its simplest embodiment, golf club head of this invention is asolid bar capable of producing a fundamental tone when struck at aparticular spot. The bar may be made of any material capable ofproducing such a fundamental tone, including metals, ceramics, polymers,and glass. Preferred materials include aluminum, bronze, brass, andglass because of their strength, weight, and ability to produce a clear,ringing tone of pleasing pitch. Preferred materials include materialshaving sound qualities similar to aluminum. To lower the tone producedby a solid bar head, the back (the side opposite the striking face) canhave a portion carved out. The carving can form any shape, including anarch, triangle, diamond, or a square among others. The apex of thecarved-out shape can correspond to the sweet spot on the face of theclub. Preferably, the carved-out portion is an arch to most closelymirror the shape of the golf ball.

[0051] In another embodiment of this invention, the head of the golfclub is made of a single piece of solid material having two free endsthat face, but do not touch each other at the back of the head to form aspace between each other. The edges of the two free ends may beparallel, or may be slanted relative to one another. In addition, thetwo free ends form part of a cylindrical hole in the head that passesthrough the entire head from the top of the head to the bottom. Thecross-section of the hole may be any shape, including but not limited tocircular, triangular, rectangular, square, or hexagonal. In anembodiment of this invention, the cylindrical hole is a circle. In anembodiment of this invention, the hole is an arc or a “T” (see FIGS. 9Aand 9B). The overall shape of the head, as seen from above, can also beany shape, symmetrical or not. Preferably, the two free ends and thecylindrical hole form a c-shape in which the ‘c’ may be multifaceted.(e.g. triangular, square, rectangular, pentagonal, hexagonal, octagonaland the like) or round, as long as the face of the head is planar alongthe length of the sweet spot. In this embodiment, the tone that isproduced by the golf club head may be changed (tuned) in several ways;by choice of head material, by removing material from the back portionof the head or the face, by changing the size of the space between thefacing free ends, and by changing the size of the cylindrical hole. Inall embodiments of this invention, the hole is large enough to allow thehead to vibrate and produce a detectable tone or note. In an embodimentof this invention, the hole is about as long, from head to toe, as thedistance between the nodes, and is optionally adjacent to one or bothnodes. The size of the area that functions more similarly as the sweetspot correlates with the length of the hole. Preferably the length ofthe hole is large.

[0052] As the size of the hole increases, the tone produced by the headdecreases in pitch. As the space between the free ends increases, thetone produced by the head increases in pitch. As the distance betweenthe face of the club head and the edge of the hole decreases, the toneproduced by the head decreases in pitch. In an embodiment of thisinvention, in one or more heads, the distance between the face of theclub head and the edge of the hole and the size of the space areselected wherein the clubs with different distances and space sizesproduce about the same tone. In one embodiment, two or more clubsproducing the same tone comprise a set. The hole dimension and placementare selected to not interfere with shaft attachment.

[0053] In an embodiment of this invention, the free ends on the sides ofthe space are not perpendicular to the bottom of the head or notparallel to each other. Preferably the toe and heel portions of thehead, as divided at the location of the center of the space, are aboutequal in weight. In an embodiment of this invention, the hole and/orspace is designed to prevent creating a sight line through the head,such as in a step pattern.

[0054] In an embodiment of this invention, a head and/or a club complieswith United States Golf Association regulations (The Official Rules ofGolf/by the United States Golf Association and the Royal and AncientGolf Club of St. Andrews, Scotland (1993)).

[0055] The vibrational properties of a given shaft can be altered bychanging its length, thickness, or material. In addition, a shaft may bea constant-diameter rod, or it may be tapered. Preferably, the shaft istapered (from thick to thin from its free end (top) to its attached end(bottom), to confer added stability to the club head. The degree oftaper can vary widely. Resonant materials useful for the shaftsdescribed herein are hardwoods, including but not limited to pernambuco,rosewood, vermillion, granadillo, ebony and osage orange, as well assteel, graphite, glass fiber, carbon fiber, plastic, fiber-reinforcedplastic, or Keylon™.

[0056] The shaft of this invention may optionally comprise a roundedknob at its top end that is adapted to fit against the golfer's navalwhile the golf club is in use. This rounded knob imparts additionalstability to the club during use. The knob may be permanently affixed tothe top of the shaft, or it may be removable. In one embodiment, therounded knob is attached to a tapered removable segment, the narrow endof which is inserted into a tapered recess in the top of the shaft thatis designed to accept the tapered removable segment.

[0057] The shaft may be directly connected to the head using anyconnection method known in the art. Means utilized to secure the shaftto the head are selected to not interfere with the hole. In a club ofthis invention, the shaft may be attached directly to the head, or via atapered connector piece known as a hosel. In an embodiment of thisinvention, a hosel is permanently attached to the head, or the headcomprises a hosel. In an embodiment, the hosel is milled or machinedfrom the same piece of material as the head.

[0058] Connection methods can be selected to allow maximal vibration orto dampen vibration transferring to the shaft. For example, the shaftmay be glued to the top of the head, or threaded, pinned, orfrictionally held within a hole in the head at the vibratory node. Sucha hole into which the shaft is inserted may be formed perpendicular tothe top surface of the head, or may angle towards the toe of the head.Preferably the shaft and securing mechanism protrude into the head byless than about half the thickness of the head. In an embodiment of thisinvention, the shaft and securing mechanism are inserted at location andangle such that half of the shaft and securing mechanism embedded in thehead is on the toe side of the node and half is on the heel side of thenode. In an embodiment of this invention, the shaft is inserted farenough back from the face to not interfere with sound and/or golfingqualities.

[0059] Preferably, the head has a shaft hole formed at the vibratorynode nearest the heel portion and is tapered from wide to narrow fromthe top to the bottom. The shaft, which is similarly tapered, slidesinto the shaft hole. In one embodiment of the club of this invention,the shaft is frictionally engaged in the shaft hole such that it issecure under normal use, but removable with the application ofsufficient pulling force in combination with the counter-clockwiserotation of the shaft. The shaft may also be tightened or loosened fromthe head using a slight turning motion that can be facilitated by usinga wrench on an optionally hexagonally shaped (or other shape) nut builtinto the shaft or the hosel, when present. In another embodiment, theshaft and the head both have pinholes that are aligned when the shaft isinserted into the shaft hole. A set pin is then passed through both theshaft pinhole and the head pinhole to permanently secure the shaft tothe head.

[0060] Alternatively, the bottom of the head comprises a bottom recessthat is approximately the diameter and depth of a bolt (screw) head andis in alignment with the shaft hole. A narrower through-hole passesthrough the center of the bottom recess such that the threaded end of abolt, when inserted through the bottom recess from the bottom side ofthe head, passes through the through-hole. If the bottom end of theshaft has a threaded hole to match the bolt threads, the bolt is used tosecure the shaft to the head. Again, an optional nut can be incorporatedinto the shaft or hosel above the section that is inserted into theshaft hole and used with or without a wrench to aid in securing theshaft to the head, or loosening the shaft from the head.

[0061] One of ordinary skill in the art will recognize that any of thesecuring means described herein can be used alone or in combination tosecure the shaft to the head. Numerous other attachment means exist inthe art, and may be used with the golf club of this invention. Inaddition, these methods may be used in embodiments in which a hosel isused as an intermediate piece between the shaft and the head. Inpractice, a particular shaft is fitted with a hosel and the shaft-hoselpair is then matched with a head such that the pair and the head arematched and no, or minimal vibrations are felt in the grip of the shaftwhen a golf ball is stuck at the sweet spot on the club head face. Theuse of a hosel to secure the shaft to the head imparts additionalstability to the golf club to prevent ‘wobble’ (rotation) of the headwhen a ball is hit at a spot other than the sweet spot.

[0062] The weight and balance of a golf club head between its face andits back and/or between its toe and heel can affect the smoothness andconsistency of a golf swing. Ways to affect this balance includechanging the distribution of weight between the face and the back, andthe toe and the heel of the head. Heads of the golf club of thisinvention weight approximately 250 g to about 500 g. Preferably, thehead of the golf club of this invention weights about 280 g to about 440g. In an embodiment of this invention, the head weight is between about330 g and about 340 g, or between about 290 g and about 310 g.Additional control is imparted to the head by ‘back weighting’ the club,i.e. by positioning the shaft such that more head weight is behind(towards the back of) the shaft than in front of it (towards the face).FIGS. 2-4 and 8-9 illustrate back-weighted heads. Furthermore,additional weight can be added to the back of the club head by addingweighted plugs behind the through-hole and adjacent to the two free endsthat face, but do not touch each other at the back of the club head. Inone embodiment of this invention, a golf club head is made of a two ormore materials. In the practice of this invention, the second materialis more dense than the first material and is inserted inside the head toincrease the weight of the head. In one embodiment, a second material isa brass insert. Materials in addition to a first material preferably donot interfere substantially with production of tones and/or vibrations.

[0063] It may also be desirable to impart spin to a golf ball when it isstruck. Top spin, for example, helps to minimize skipping, jumping, orsliding of the ball as it moves away from the face of the head.Imparting spin is possible by changing the angle (loft) of the face ofthe head from 90 degrees (relative to the plane of the ground) to lessthan 90 degrees (towards the back of the head) by about 1 degree toabout 65 degrees. For putters, the optimal angle is approximately 1-4degrees. For chippers, angles of 1-30 degrees are preferable.

[0064] This invention provides golf club heads that are not solid. Thisinvention also provides a golf club head which does not have an opensight line. This invention provides golf club heads having a zigzag orstep-type hole and/or space.

[0065] Golf club heads of this invention have two nodes. One node isutilized to attach a shaft to construct a right-handed club, and theother to construct a left-handed club.

[0066] This invention provides a method for making a golf club headcomprising shaping the head from a resonant material wherein the headhas at least one vibratory node and a hole adapted for attaching a shaftat the vibratory node, wherein the head produces a tone when struck by agolf ball. This invention also provides a method for making a golf clubcomprising: shaping a golf club head from a resonant material whereinthe head has at least one vibratory node whereby the head produces atone when struck by a golf ball; shaping a hole adapted for attaching ashaft at the vibratory node; and attaching a shaft made of a resonantmaterial to the head in said hole.

[0067] This invention provides a golf club head having an open sightline comprising: a head capable of producing a tone when struck by agolf ball, wherein the head has an open sight line, at least onevibratory node, and a hole adapted for attaching a shaft at thevibratory node. This invention provides a method for evaluating a golfclub swing comprising: providing a golf club comprising a head having anopen sight line, attached to a resonant material shaft, and a hole inthe head, wherein the open sight line has an open sight distance ameasured from head to toe; applying a stripe on a floor or groundsurface whereby the width of the stripe is about equal to or less thanthe open sight distance of said open sight line; swinging said club oversaid stripe; and detecting and analyzing the amount and pattern of saidstripe visible through said open sight line of said head. Preferably,the stripe is visible to the human eye and straight. In an embodiment ofthis invention, the sweet spot is centered at the axis aboutperpendicular to the face and parallel with the bottom of the head, atthe center of the open sight line, the hole, and/or the space. Markingmethods include using paint and/or tape. In an embodiment of thisinvention, the width of the stripe is about equal to the width of thehole or the space, in the direction from head to toe, of the head usedfor practicing swinging. In an embodiment of this invention, thestraightness of said swing is evaluated.

[0068] In an embodiment of this invention, the method for evaluating aswing also comprises: placing a golf ball on the floor or ground surfacenear or adjacent to an end of the stripe, before the swinging step;hitting the golf ball with the club resulting from the swinging step;and detecting and analyzing a tone produced by the club head and/ordetecting vibration of said shaft. The ball is placed near or adjacentto an end of the stripe whereby swinging the head over the stripewhereby about the entire width of the stripe is visible through the opensight line during the swing, leads to the ball hitting the club in thesweet spot. In an embodiment of this invention, the swing is evaluatedfor accuracy at hitting said ball with the sweet spot of the club.

[0069] The particular dimensions of a head of this invention, canoptionally be calculated, as is known in the art, after selecting amaterial, using the density of the material. Heads can also optionallybe designed to meet regulations of the PGA, and then the materialselected after calculating what density is required to construct thedesigned club at a selected weight.

[0070] The following figures and examples are exemplary only and are notmeant to limit the invention to any particular configuration.

[0071]FIG. 1A is a top angled view of one embodiment of a head of a golfclub of this invention. Head 105 comprises a solid bar having foursides: face 115, toe 112, heel 110, and back 130, top 101, and bottom102. Cutout 134 is positioned on the center of back 130 and is alignedwith sweet spot 116 on face 115. Shaft hole 150 is located along thenodal line 160 close to heel 110. FIG. 1B is the top view of oneembodiment of a head of a golf club of this invention. Head 105comprises a solid bar having four sides: face 115, toe 112, heel 110,and back 130, top 101, and bottom 102. Cutout 134 is positioned on thecenter of back 130 and is aligned with sweet spot 116 on face 115. Shafthole 150 is located along the nodal line 160 close to heel 110.

[0072] FIGS. 2A-2C are illustrations of a golf club head of thisinvention. FIG. 2A is the top view. Head 105 comprises a solid barhaving four sides: face 115, toe 112, heel 110, and back 130, top 101,and bottom (not shown). Cutout 134 is positioned on the center of back130 and is aligned with sweet spot (not shown) on face 115. Shaft hole150 is located at the node close to heel 110. FIG. 2B is a side viewfrom the back. Head 105 comprises a solid bar having four sides (face(not shown), toe (not shown), heel 110, back 130), top 101, and bottom102. Cutout 134 is positioned on the center of back 130 and is alignedwith the sweet spot (not shown) on the face (not shown). The cutout 134has an additional inside cutout 255. FIG. 2C is a side view from theface 115 of the golf club head. Head 105 comprises a solid bar havingfour sides: face 115, toe 112, heel 110, and back (not shown)), top 101,and bottom 102. Sweet spot 116 is shown on the face 115.

[0073]FIG. 3 illustrates a perspective view of one embodiment of a golfclub of this invention. The golf club comprises a head 105 and a shaft140 having grip 131 attached to head 105. Head 105 comprises a singlepiece of solid material having two free ends 132 that face, but do nottouch each other at the back 130 of the head to form space 125. Thegeneral shape of head 105 is a “C”, although other shapes are within thescope of this invention. Cylindrical hole 120 passes through the headfrom top to bottom and is aligned with sweet spot 116 on face 115. Thearea capable of responding similarly to the sweet spot 116 is bound bysweet spot area lines 224. Nodal line 160 is a line along which thereare no to minimal vibrations when face 115 is struck at sweet spot 116,e.g., with a golf ball. Shaft hole 150 is disposed along the nodal line160 close to the heel edge 110 of the head and is adapted to receiveshaft 140, optionally via hosel 145. The toe 112, heel 110, and back 130surfaces may have optional contours 135. Head 105 further comprisesalignment-marking 155 which is located on top surface 101 near face 115and in alignment with the center of sweet spot 116. In this embodiment,the hosel further comprises an optional hosel nut 147 in the shape of ahexagon, which is used to assist in tightening and/or loosening theshaft and head. The angle of the face 115 to the ground is changed from90 degrees by 2 degrees, i.e., it is 88 degrees.

[0074] FIGS. 4A-4C show the club head of FIG. 3 from other angles. FIG.4A shows the bottom surface 102 of the head depicted in FIG. 3. Optionalbottom recess 152 and through-hole 154 are used for securing the shaftto the head. FIG. 4B is a front view of the head depicted in FIG. 3,showing optional contours 135. Bottom surface 102 is substantiallyplanar, although the transitions to toe 110 and the heel 112 arerounded. FIG. 4C shows a side view of the head depicted in FIG. 3. Theheel 110 is rounded. Face 115 is substantially planar and is angledtoward the back 130 from bottom 102 to top 101 by about 2 degrees.

[0075]FIGS. 5A and 5B illustrate a golf club head of this invention.FIG. 5A is a top view. The golf club head 105 comprises a single pieceof solid material having two free ends 132 that face, but do not toucheach other at the back 130 of the head to form space 125. The generalshape of head 105 is a “C”, although other shapes are within the scopeof this invention. Cylindrical hole 120 passes through the head from topto bottom and is aligned with the sweet spot (not shown) on face 115.Shaft hole 150 is at the node close to the heel edge 110 of the head105. The toe 112, heel 110, and back 130 surfaces may have optionalcontours 135. Head 105 further comprises alignment-marking 155 which islocated on top surface 101 near face 115 and in alignment with the sweetspot (not shown). FIG. 5B shows a side view of the head 105 having top101, contours 135, face 115, sweet spot 116, and bottom 102.

[0076] FIGS. 6A-6D show other “C”-shaped golf club head embodiments ofthis invention. FIG. 6A depicts a golf club head 105 in which all of thesides: face 115, toe 112, heel 110 and back 130, are planar. FIG. 6Bdepicts a golf club head, in which face 115 is planar, but toe 112, heel110, and back 130 are rounded. FIG. 6C depicts a golf club head 105 inwhich the face 115, toe 112, and heel 110 are planar and the back 130 isangular. FIG. 6D depicts a golf club head 105 in which all of the sidesare substantially planar but with rounded transitions between each side.Each of the embodiments pictured in FIGS. 6A-6D show a circularcylindrical hole 120, although is it readily apparent to one of ordinaryskill in the art that other shapes are possible. In FIG. 6D, twoexamples of open sight distances 200 and 201 are labeled. The sweet spot(on face, not shown) is centered on the sweet spot axis 202 which, onthis head, runs through the center of the hole 120 and the space 125.The alignment marker 155, which is also in line with the axis, is shownon the top surface 101. In FIGS. 6A-6D, the heads 105 also show a hole150 at the node close to the heel 110, which is useful for attaching ashaft (not shown). Parts are numbered consistently in FIGS. 6A-6D.

[0077]FIGS. 7A and 7B illustrate a “C”-shaped golf club head of thisinvention. FIG. 7A is a top view. The golf club head 105 comprises asingle piece of solid material having two free ends 132 that face, butdo not touch each other at the back 130 of the head to form space 125.Cylindrical hole 120 passes through the head from top to bottom and isaligned with the sweet spot (not shown) on face 115. Shaft hole 150 isat the node close to the heel edge 110 of the head 105. The toe 112,heel 110, and back 130 surfaces may have optional contours 135. The freeends 132 can also have optional contours 230. FIG. 6B shows a side viewof the head 105 having top 101, contours 135, face 115, sweet spot 116,and bottom 102.

[0078]FIGS. 8A and 8B illustrate a “C”-shaped golf club head of thisinvention. FIG. 8A is a top view. The golf club head 105 comprises asingle piece of solid material having two free ends 132 that face, butdo not touch each other at the back 130 of the head to form space 125.Five-sided pentagonal hole 120 passes through the head from top tobottom and is aligned with the sweet spot (not shown) on face 115. Shafthole 150 is at the node close to the heel edge 110 of the head 105. Thetoe 112, heel 110, and back 130 surfaces may have optional contours 135.FIG. 8B shows a side view of the head 105 having top 101, contours 135,face 115, sweet spot 116, and bottom 102.

[0079] FIGS. 9A-9C illustrate another “C”-shaped golf club head of thisinvention. FIG. 9A is a top view. The golf club head 105 comprises asingle piece of solid material having two free ends 132 that face, butdo not touch each other at the back 130 of the head to form space 125.Arc-shaped hole 120 passes through the head from top to bottom and isaligned with sweet spot (not shown) on face 115. Shaft hole 150 is atthe node close to the heel edge 110 of the head 105. The toe 112, heel110, and back 130 surfaces may have optional contours 135. FIG. 9A alsoshows an optional damping hole 255 extending from the top 101 to thebottom (not shown). FIG. 9B shows a side view of the head 105 having top101, contours 135, face 115, sweet spot 116, and bottom 102. The edgesfrom the top 101 to both the toe 112 and heel 110 all the way to thebottom 102 are contoured 135 and rounded. FIG. 9C shows a side view fromthe back 130. An optional damping hole 256 is shown through the back 130to the hole (not shown).

[0080]FIG. 10 illustrates the optional rounded knob attached to the topof the shaft of the golf clubs of this invention. Rounded knob 175 isdesigned to fit into the golfer's navel during use. Knob 175 is attachedto tapered fitting 170, which is inserted into tapered shaft opening180. Optional metal cap 165 covers the top end of shaft 140, coveringthe tapered end 212, which is fitted into the shaft grip 211.

[0081]FIG. 11A-11C illustrate a head 105 having the hole 320 and 420 andspace 325 and 425 designed in a step pattern to prevent creating an opensight line from the top 101 to the bottom 102 of the head 105. The lowerhole section 420 and the lower space section 425 are not visible fromthe top and are shown with dashed lines. FIG. 11A is a top view andFIGS. 11B and 11C are cross sections as marked B-B and C-C,respectively, in 11A. In FIG. 11B a hole opening 300 connects the upperhole section 320 and the lower hole section 420 while preventing thefree ends 132 from contacting and preventing the formation of an opensight line. In FIG. 11C a space opening 301 connects the upper spaceopening 325 with the lower space opening 425 while preventing the freeends 132 from contacting and preventing the formation of an open sightline.

EXAMPLE 1

[0082] Seven heads of the design shown in FIG. 6A were constructed withholes of varying diameter, from one and three eighths inches to one andfive eighths inches by forty thousandth increments. The nodes were inthe same locations for all heads. The pitch of each head was different.

EXAMPLE 2

[0083] A head of the design shown in FIGS. 5A-B was constructed ofaluminum T60-61. The locations of the vibratory nodes was determined bysuspending the head, top up, sprinkling sawdust on the top, and strikingthe face, on the sweet spot, with an item capable of causing the head tovibrate, e.g., a golf ball. The sawdust pieces moved as a result of thevibrations, such that the sawdust collected over the nodes, where no orminimum vibrations occurred. The head was anodized. A shaft was turnedfrom pernambuco and constructed to be attached to the head using aturning motion.

EXAMPLE 3

[0084] A head of the design shown in FIGS. 2A-C was constructed ofbronze.

EXAMPLE 4

[0085] A head of the design shown in FIGS. 7A-B was constructed ofbrass.

EXAMPLE 5

[0086] A head of the design shown in FIGS. 8A-B was constructed ofaluminum.

EXAMPLE 6

[0087] A head of the design shown in FIGS. 9A-B, without the dampingholes, was constructed of aluminum.

[0088] Those skilled in the art will appreciate that the inventiondescribed herein is susceptible to variations and modifications otherthan those specifically described. It is to be understood that theinvention includes all such variations and modifications which fallwithin its spirit and scope. Golf club shaft and head designs,attachment mechanism, and materials useful for making golf clubs andheads are intended to be within the scope of this invention. Further,while a number of statements appear throughout this applicationregarding possible mechanisms by which, for example tones are producedor dampened, or vibrations are produced transferred or dampened, theinventors do not wish to be held to any particular theory regarding theoperation of the device of this invention.

1. A golf club head capable of producing a tone when struck by a golfball, said head having at least one vibratory node, and a hole or hoseladapted for attaching a shaft at said vibratory node, said head having atop, bottom, face, back, heel, toe, and sweet spot.
 2. The golf clubhead of claim 1 made from a material selected from the group consistingof metals, ceramics, and crystalline glass.
 3. The golf club head ofclaim 1 made from a material selected from the group consisting ofaluminum, brass, and bronze.
 4. The golf club head of claim 1 weighingbetween about 250 grams and about 500 grams.
 5. The golf club head ofclaim 1 made of a single piece of metal having a substantially planartop and bottom and two free ends which face but do not touch each otherat the back of said head such that a space is formed between said twoends.
 6. The golf club head of claim 1 having a cylindrical hole formedtherethrough from top to bottom.
 7. The golf club head of claim 6wherein the distance between the face of the head and said cylindricalhole is between about three sixteenths and about one inch.
 8. The golfclub head of claim 1 that is solid.
 9. The golf club head of claim 1constructed and adapted to produce a selected musical note when itstrikes a golf ball at said sweet spot.
 10. The golf club head of claim1 wherein said face further comprises mill lines.
 11. The golf club ofclaim 1 wherein the portion of the head towards the back of said hole orhosel is heavier than the portion of the head towards the face of saidhole or hosel.
 12. The golf club head of claim 1 also comprising atapered connector having one end adapted to fit into said hole and oneend adapted to receive an end of a shaft.
 13. A golf club comprising: ahead of claim 1 and a shaft made of a resonant material attached to saidhead at said hole or hosel.
 14. The golf club of claim 13 wherein saidshaft is made of a material selected from the group consisting ofhardwood, steel, graphite, glass fiber, fiber-reinforced plastic,plastic, and carbon fiber.
 15. The golf club of claim 14 wherein saidshaft is made of hardwood.
 16. The golf club of claim 15 wherein saidhardwood is selected from the group consisting pernambuco, rosewood,vermillion, granadillo, ebony, and osage orange.
 17. The golf club ofclaim 13 wherein said shaft comprises a rounded top designed to fitagainst the navel of a golfer.
 18. The club of claim 17 wherein saidrounded top is capable of transferring vibration from said shaft to saidnavel.
 19. The golf club of claim 13 which is a putter.
 20. The golfclub of claim 13 which is a chipper.
 21. A method of striking a golfball comprising: positioning a golf club of claim 13 adjacent to saidgolf ball; and striking said golf ball with said head of said golf club,whereby a musical tone is produced.
 22. A method of determining when agolf club has struck a golf ball at the golf club head's sweet spot,said method comprising: striking said golf ball with a golf club ofclaim 13; and determining that said golf ball has been struck at saidgolf club's sweet spot when detecting said golf club is producing amusical tone indicative of having struck said ball at said sweet spot.23. The method of claim 22 also comprising determining that said golfball has been hit by said golf club's sweet spot by detecting minimum orno vibration of the shaft.
 24. The golf club head of claim 1 having anopen sight line.
 25. A method for evaluating a golf club swingcomprising: a) providing a golf club comprising the head of claim 24attached to a resonant material shaft at said hole or hosel, said opensight line having an open sight line width, as measured from the headside to the toe side; b) applying a stripe on a surface whereby thewidth of said stripe is about equal to or less than said open sight linewidth; c) swinging said club over said stripe; and d) detecting andanalyzing the amount and pattern of said line visible through said opensight line.
 26. The method of claim 25 comprising evaluating thestraightness of said swing.
 27. The method of claim 25 also comprising:a) placing a golf ball on said surface adjacent to an end of saidstripe, before said swinging step; b) striking said golf ball with saidclub, resulting from said swinging step; and c) detecting and analyzinga tone produced by said club head and/or a vibration of said shaft. 28.The method of claim 27 comprising evaluating the accuracy of strikingsaid ball at the sweet spot of said head.
 29. A method for making a golfclub head comprising: shaping said head from a resonant material whereinsaid head has at least one vibratory node and a hole or hosel adaptedfor attaching a shaft at said vibratory node; and wherein said headproduces a tone when struck by a golf ball or wherein said headcomprises two free ends which face but do not touch each other at theback of said head such that a space is formed between said two ends. 30.A method for making a golf club comprising: a) making a golf club headof claim 29; and b) attaching a shaft made of a resonant material tosaid head at said hole or hosel.
 31. A set of golf clubs, each clubconstructed and adapted to produce separate selected musical notes wheneach is struck by a golf ball.
 32. The set of golf clubs of claim 31,each club having a cylindrical hole through the head of each club fromtop to bottom, wherein the pitch of said musical note is determined bythe size of said cylindrical hole.
 33. The set of golf clubs of claim 31having different colors indicative of said selected musical note eachproduces when it is struck by a golf ball.
 34. A method for striking agolf ball on a course having particular conditions affecting golf ballspeed, with a golf club selected from the set of claim 31, said methodcomprising: determining the condition of the golf course and selecting aclub from said set of clubs in accordance with said conditions.